Mechanism for use in conjunction with the intake opening of a water jet propelled vehicle



3,253,567 AKE May 31, 1966 R. A. PATTON, JR

MECHANISM FOR USE IN CONJUNCTION WITH THE INT OPENING OF A WATER JET PROPELLED VEHICLE 5 Sheets-Sheet 1 Filed Sept. 4, 1963 hid-wife): ay )6. Quito TR 65 $547? WQWEW.

y 1966 R. A. PATTON, JR 3,253,567 I MECHANISM FOR USE IN CONJUNCTION WITH THE INTAKE OPENING OF A WATER JET PROPELLED VEHICLE Filed Sept. 4, 1963 5 Sheets-Sheet 2 May 31, 1966 R. A. PATTON, JR 3,253,567

MECHANISM FOR USE IN CONJUNCTION WITH THE INTAKE OPENING OF A WATER JET PROPELLED VEHICLE 5 Sheets-Sheet 5 Filed Sept. 4, 1965 R. A. PATTON. JR

May 31, 1966 4 MECHANISM FOR USE IN CONJUNCTION WITH THE INTAKE OPENING OF A WATER JET PROPELLED VEHICLE 5 Sheets-Sheet 4 Filed Sept. 4, 1963 LLLL L May 31, 1966 R. A. PATTON, JR 3,253,567

MECHANISM FOR USE IN CONJUNCTION WITH THE INTAKE OPENING OF A WATER JET PROPELLED VEHICLE Filed Sept. 4, 1963 5 Sheets-Sheet 5 60 58 T fl;

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United States Patent 3,253,567 MECHANISM FOR USE IN CONJUNCTION WITH THE INTAKE OPENING OF A WATER JET PRO- ]PELLED VEHICLE Roy A. Patton, In, 6030 North Shore Drive, Grabill, Ind.

' Filed Sept. 4, 1963, Ser. No. 306,521

14 Claims. (Cl. 115-.5)

This invention relates generally to mechanism'for use in conjunction with the intake opening of a water jet propelled vehicle, and more specifically to mechanism for improving the operation of water intake in such a vehicle.

One type of jet propelled vehicle is a boat provided with an engine driven pump which draws water through an intake opening located in the bottom of the boat, imparts a high velocity to the water, and discharges the water from the rear of the boat. This high velocity discharge of water from the rear of the boat provides the boats locomotion. The water drawn through the intake opening passes into the pump with suflicient velocity to suspend small objects, Weeds and other debris in its stream, and thereby carry them into the pump, causing impairment of pump operation and possibly pump damage.

This difficulty has been reduced to a certain extent by locating the intake opening in the bottom of the boat generally parallel with the direction of flow of water adjacent the hull. .Therefore, debris must be sucked into the opening rather than merely impinging on the opening in order to reach the pump. Devices have also been proposed for straining the fluid before it passes into the intake opening, but these have not completely solved this problem. Those strainers that are effectual soon become clogged with weeds or debris and thereby restrict the flow of liquid into the pump; this restricted flow can greatly reduce the maximum speed or acceleration of the boat. Other straining devices are not easily clogged with weeds and debris but are ineffectual in protecting the pump.

Another difliculty with prior strainers and intake openings is that they are not adjustable. Eflicient jet boat operation depends upon the availability and the delivery of water at the pumps capacity at all times and under all phases of boat operation. Jet boats heretofore have been designed with an intake opening of a size that insures efficient operation only under a small range of operating conditions. When the boat is standing still, just prior to acceleration, or is moving slowly, the opening is sulficient if it is large enough to permit the pumps fluid capacity to flow therethrough. As the boat picks up speed, the relative velocity of the water aids in the delivery of water to the pump as long as the flow remains generally laminar. As soon as turbulence develops, the fluid will vortex, froth, or in other ways develop air pockets in the water entering the intake opening and thereby present to the pump a mixture of air and water rather than water alone. Such a mixture in flowing through the pump may have deleterious effects on the pump and will cause a loss of thrust. It is therefore desirable under some conditions to have a somewhat larger intake opening than that theroetically efficient for slow speeds so that an increased volume of mixture may be presented to the pump, thereby regaining a part of the water volume lost. At highly turbulent planing speeds, the relative velocity of the fluid impinging on the intake opening aids in the compression of the waterair mixture by the pump resulting in a gain in efliciency. Opposing this gain in efliciency is a drag and a corresponding loss of power caused by the compression of the airwater mixture. It is therefore desirable to compress only that amount of mixture that will result in the proper amount of water being fed to the pump. This calls for a reduction of the size of the intake opening, possibly beyond the size used for slow speeds. Heretofore, there has been no known device which can remedy this problem by adjusting the size of the intake opening. A further difficulty with prior strainers and intake openings becomes apparent when the boat heels over while turning corners and the intake opening or a part thereof comes out of the water. As soon as any part of the intake opening is not covered by Water, air will be sucked into the pump, causmg a great loss of power.

Although the above discussion ofthe prior art has concerned a jet propelled boat, it is equally applicable to other marine or amphibious vehicles such as amphibious tanks and cargo carriers, hydrofoil ships, and other liquid jet propelled vehicles.

It is accordingly an object of this invention to provide a strainer for use with a liquid jet propelled vehicle that is easily cleaned.

It is another object of this invention to provide mechanism for selectively varying the size of an intake opening of a liquid jet propelled vehicle.

It is another object of this invention to provide mechanism which minimizes the tendency of the intake drawing air upon a liquid jet propelled vehicle heeling over in a turn.

It is a further object of this invention to provide a strainer and an intake opening combination which is easily cleaned, is selectively variable in size, and does not draw air under normal operating circumstances.

It is a further object of this invention to provide a strainer and an intake opening combination, as mentioned above, that will insure the most efficient jet pump operation under all conditions and in all phases of vehicle operation.

The above-mentioned and other features and objects of this invention and the manner of attaining them will be come more apparent and the invention itself will be best understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a longitudinal cross-sectional view of a liquid jet propelled boat embodyingthe present invention;

FIG. 2 is a fragmentary isometric view of the bottom of the hull of a liquid jet propelled boat showing the present invention;

FIG. 3 is a fragmentary bottom view of the structure shown in FIG. 2;

FIG. 4 is a fragmentary sectional view taken substantially along section line 4-4 of FIG. 3;

FIG. 5 is a fragmentary, isometric sectional view taken substantially along section line 5--5 of FIG. 3;

1FIG. 6 is a top view of the slidably attached closure p ate;

FIG. 7 is a trailing end view-of the closure plate of FIG. 6;

FIG. 8 is a fragmentary sectional view taken substantially along section line 8-8 of FIG. 3; and

FIG. 9 is a fragmentary illustration, partially in crosssection, taken substantially along section line 9-9 of FIG. 8.

Referring to the figures of the drawings, a liquid, jet propelled boat is shown, as an example and in no way limiting, having a hull 10, a conventional marine engine 12 mounted generally centrally and operatively connected 'by a shaft 14 to a pump 16 having a discharge opening 18 at the rear of the boat. Located in the bottom of the hull 10 is an intake opening 20 (shown rectangular) which allows liquid to pass to the pump 16. Covering the opening 20 is a strainer 22 to prevent weeds, small foreign objects and other debris from flowing into the pump 16. Two laterally spaced and parallel sister keels or deflectors 26 are shown extending longitudinally with the hull adjacent the opposite longitudinal edges of opening 20 for at least the length of the latter.

Each deflector 26 is composed of an elongated flat or keel portion 28 and a lateral mounting flange 30, and is secured to the underside of the hull 10 by means of a suitable number of screws 31 which pass through the flange into the hull. Each keel portion 28 has its width depending perpendicularly from the bottom of the hull 10 with the length thereof being disposed adjacent to and parallel with the respective edge of the opening 20. Also, the keel portion 28 has a length preferably longer than said opening 20, and is positioned such that it extends for at least the entire length of the opening 20. As shown in FIG. 3, the aft edges of the keel portions 28 are positioned flush with the aft end of the opening 20, while the forward ends thereof extend forwardly of the opening 20. Otherwise, the keel portions are positioned substantially parallel to the longitudinal axis of the hull 10.

In a specific application, keel portions 28 may be slightly angularly disposed with respect to each other, the leading ends of portions 28 being farther apart than the trailing ends thereof. They also may be angularly disposed from the perpendicular or of various lengths relative to opening 20 as will become-apparent from the following description. The leading ends 29 of portions 28 are curved to decrease drag and for increased safety of operation.

Parallel with the longitudinal edge of and spanning the opening 20 are a plurality of equally spaced and dimensioned elongated members or straining bars 32, unattached at their trailing ends 34 and fixedly attached by means of adhesive, welding, etc., at their leading ends 36 to the hull at the leading edge 38 of.opening 20. Bars 32 are made of a material that is rigid, highly elastic and resilient, preferably stainless steel, so as to protect against corrosion and at the same time leave members 32 free to vibrate in the turbulent water flowing past. Members or bars 40 identically dimensioned and constructed as members 32, excepting an added length to accommodate their means of attachment at their leading ends, are alternately positioned in spaced relation with members 32; together they form a strainer or grate covering opening 20.

The leading ends 42 of members 40 are positioned in recessed slots 44 in hull 10 which open through the edge 38. Also, these ends 42 are pivotally connected to hull 10 by means of suitable pins 46 which extend perpendicularly to the longitudinal hull axis. Bars 32 are disposed at the outermost and central positions of the strainer.

Bars 40 lie between members 32, having unattached trailing ends 48, are capable of pivotal movement about the axes of respective elements 46, in the direction of arrows 50. Members 40, the same as members 32, vibrate in the turbulent waters flowing along the underside of the hull 10. The amplitude of vibration, however, is larger than that of members 32 because of the less rigid mounting thereof. Besides this vibratory motion, bars 40 can be moved individually and selectively by means of pins 51 as shown in FIGS. 5, 8 and 9. Pins 51 are provided with heads 55 which fit into T-shaped slots 57 in the aft ends 48 of bars 40 and project upwardly through sealed apertures 59 in the hull 10. Springs 53 are fitted over pins 51 and are compressed between the hull 10 and retaining nuts 5311 on the pins. Therefore, when in normal position, pins 51 do not interfere with the vibratory movement of bars 40. However, the depression of pins 51 will move members 40 outwardly away from hull 10 as shown by the dashed line bars 40a in FIGS. and 8. At position 40a, the members 40 will either be relatively stationary or vibrate with less amplitude than in their normal positions.

Slidably inserted into inwardly facing and opposing grooves 54 in flanges 30 of keels 26 which form an elongated slot with hull extending from the trailing edges of keels 26 parallel to the longitudinal distance of opening 20 is a closure plate 52 (see FIGS. 3, 5 and 8). Closure plate 52, shown alone in FIGS. 6 and 7,

has a plurality of parallel slots 56 extending through plate 52, equal in number to the cumulative total of members 32 and 40 but slightly wider than the dimensions thereof, and opening through plate edge 58. Bars 32 and 40 lie within the slots 56 and juxtaposed with the tines 60 of forked plate 52, thereby closing a portion of opening 20. Closure plate 52 can be selectively positioned to cover a portion of opening 20 as desired for efiicient operation of the boat (exemplified by position shown and position 62) by means of a handle shaped appendage 64 which extends beyond the inside bottom surface of hull 10. This handle 64 may be operated manually or by means of a lever or toggle system actuated hydraulically, electrically or by some similar means. As shown in FIG. 8, a two-way hydraulic power cylinder 65 is shown operatively connected to a rod 57 which is secured directly to the handle 64. The power cylinder is operated selectively by means not shown whereby the plate 52 can be moved forwardly and rearwardly to desired positions and held in such positions by means of closed valves (not shown) in hydraulic lines connected to the two ports 69 and 61 of the cylinder 65. By alternatively applying pressurized liquid to the two ports, this forward and reverse movement is achieved.

In a specific embodiment of this invention, intake opening 20 is twenty-four (24) inches long and fourteen (14) inches wide; each deflector 26 is about thirty (30) inches long; members 32 are about twenty-two (22) inches long; members 40 are about twenty-six (26) inches long; and closure plate 52 is about sixteen (16) inches square having slots 56 that are about thirteen (13) inches long. A typical depth dimension for the deflectors 26 is three (3) inches.

In operation, water is drawn through the intake opening 20 into the pump 16 wherein velocity is imparted to the water by means of the engine 12 and the water is thrust through opening 18 at the rear of the hull, forcing the hull forward in the water. As the hull is traveling on a straight course through the water at a constant rate of speed and in alignment with its motion, the size of the intake opening 20 for eificient boat operation remains constant and members 32 and 40 merely vibrate in their normal position due to the flow of turbulent water around them. This vibratory action will normally keep weeds, foreign matter and other debris from col-' lecting on the strainer while the boat is moving.

If weeds, foreign matter or debris are already attached to the strainer 22 and are not removed by the vibratory movement of members 32 and 40 nor by the velocity of the water flowing therepast, the flow of water to the pump 16 is thereby restricted and closure plate 52 would have to be positioned closer to the aft end of the hull as an increased size of the opening 20 is needed for the most efficient boat operation. However, pins 51 may be depressed to lower members 40 away from hull 10 to position 40a or to any position therebetween and there vibrate naturally because of the water flow or artificially from an oscillatory motion imparted to pins 51, until the strainer 22 is cleaned. For this purpose, members 40 can be moved either individually or in combination with each other; and with a momentary sacrifice of pump power, closure plate 52 can be slid towards the bow to help scrape off any debris, weeds or foreign matter clinging to either members 32 or 40. When the strainer 22 is cleaned, closure plate 52 will need to be moved forward from the position it had when the strainer 22 was clogged so as to decrease the size of the intake opening 20.

Turning the hull 10 while in motion results in bringing the deflectors 26 into operation. Since the usual pleasure boat will bank or heel in a turn, it is obvious that if this heel is material, the intake 20 can partially leave the water. If this happens, the pump will suck air prejudicially to water and propulsion will be lost. However, by use of the deflectors 26, the inherent sideways slippage of the boat due to centrifugal force will result in water being deflected upwardly by the then lower deflector 26 to cover the opening 20. Also, the uppermost deflector 26 will deflect water downwardly, such that the two deflectors 26 act in concert to maintain a supply of water for the opening 20. Different amounts of water can be deflected toward the opening 20 by varying the shape of the oppositely facing deflector surfaces, such as making them parabolic or otherwise curved in a plane perpendicular to the planar surfaces shown or flat surfaces angularly disposed with hull 10. The deflection of water must be great enough to supply the pump requirements. As the angle of water toward opening 20 may be more direct during a straight run, the water velocity may be greater through the opening 20, thereby allowing the use of a smaller opening 20 for the same amount of water flow therethrough. For this reason, plate 52 may have to be adjusted with any change in the angle from alignment with the direction of motion, to provide the most eflicient boat operation.

It also is evident that with any change in the angle that the water impinges on opening 20 (as in planing), or in the relative velocity of the water flowing past the hull, the velocity of water flowing through opening 20 may change. As any water in excess of the pumps capacity impinging on the opening 20 will result in drag, a less eflicient operation will result than if the same water impinged on the hull 10. Therefore, all changes in boat velocity generally require a change in position of plate 52 to maintain eflicient operation.

At high boat velocities, the Water surrounding and flowing past the hull is very turbulent. Vortexes, froth and other turbulent water formations cause the pump to inhale an air-water mixture rather than pure water, thereby resulting in a loss of power. At planing speeds, this problem is somewhat reduced as the water impinges more normally on hull 10, causing compression of these turbulent water formations and a requisite increased water flow to the pump 16. Further improvement can be had by slightly angularly positioning the deflectors 26 with respect to each other so as to form a slightly wider spacing at the forward ends thereof through which water will flow toward opening 20, thereby aiding in the compression of the air pockets in the water entering the .pump 16. Such an angular arrangement, however, must be tailored to the specific hull shape and only used where the increased power resulting therefrom is suflicient to offset the increased drag caused thereby.

This invention in its broader aspects comprises an intake opening or port in the bottom of a jet propelled boat hull which leads through a conduit into the intake end of a pump powered by a conventional marine engine, a strainer covering the opening or port, a slidable plate for selectively varying the size of the intake opening, and at least two keels or deflectors extending longitudinally of the hull for the distance of the opening.

While the pump and the marine engine and the mounting thereof within the-boat may be conventional, the remaining structure disclosed herein constitutes the invention. The size of the intake port will generally be larger than that found in prior boats for the reason that now adjustability has been designed into the port, whereas prior port sizes were chosen for optimum performance over the whole range of boat operation.

Further, the method of attachment of the individual members or rods of the strainer has been altered over any known device to improve the self-cleaning ability of the strainer and to insure the removal of weeds and the like, therefrom.

Still further, at least two relatively large keels, extending the distance of the intake opening, serve to deflect water toward the opening when the boat is heeling over in a turn to insure the availability of water to the pump at all times and to likewise exclude air from passing into the pump.

Each of these features, enumerated here singularly, combine in the functioning thereof to provide eflicient jet boat operation under all operating circumstances. The slidable plate, used to adjust the size of the intake opening, is necessary to compensate for the enlarged intake opening during the strainer cleaning process in which the elongated members of the strainer will 'be selectively moved further apart from each other, thereby increasing the area of the opening. Adjustment is also necessary when the boat is angularly disposed to its motion and the keels or deflectors are deflecting the water toward the opening, as the reuslt may be higher water velocities through the opening than when the boat is aligned with its motion. Still further, the opening must be adjusted as the boat goes into and out of planing velocities as planing may result in a more direct, hence forceful, flow of water into the intake opening as well as an increase in water velocity through the opening.

The present invention installed on hulls of other marine or amphibious vehicles or on structure other than the hull protruding into the water and operating as an intake for a liquid jet turbine will have similar operational problems, similar structure will be needed to overcome such problems and such vehicles will operate similarly to the liquid jet boat as described. For example, an amphibious vehicle to be used on land, swampy terrain and inland lakes will have more serious clogging problems due to vegetation clinging to the intake port, but will not operate at as high velocities as the jet boat described, nor will such vehicle heel over to expose its intake port to the air. On the other hand, a hydrofoil ship will have less vegetation clogging problems, but will have higher velocities, a

greater planing angle, and possibly more difficulty on turning in exposing its intake port to the air. While this invention pertains to intake ports generally for use in conjunction'with liquid jet propulsion systems, each marine or amphibious'vehicle having such a system will have its own peculiar operational requirements and as is apparent from the preceding description, this invention supplies those requirements.

While I have describedabove the principles of my invention in connection with specific apparatus, it is to be clearly understood that this description is made only by way of example and not as a limitation to the scope of my invention.

What is claimed is: I

1. In combination, a member having a longitudinal axis and a submergible intake port, a plurality of elongated parallel and spaced apart members having leading and aft ends, respectively, covering said port, said elongated members extending longitudinally of said member, alternate elongated members being pivotally connected to said member at the leading ends thereof for swinging movement toward and away from said member, the remaining alternate elongated members being fixedly connected to said member at the leading ends thereof, means for selectively pivoting the first-mentioned alternate elongated members toward and away from said member, means for deflecting water into said port in response to motion of said member in a direction at an angle with respect to said longitudinal axis, a closure plate slidably attached to said member, and means including said plate for selectively controlling the flow of fluid into said intake port.

2. In combination, a boat hull having an intake port in the bottom of said hull, said port having forward and aft ends; a strainer for covering said port, said strainer comprising a plurality of elongated members having leading and trailing ends, said members being spaced apart and parallel, said members extending longitudinally of said hull, the leading ends of first ones of said members being fixedly attached to said hull adjacent to the forward end of said port, the leading ends of second ones of said members being pivotally attached to said hull adjacent to the forward end of said port for swinging movement about axes extending transversely of said hull, said first and second members being arranged alternately; two elongated keels depending from the bottom of said hull and extending longitudinally of said hull for the distance of and along opposite sides, respectively, of said port for deflecting fluid into said port in response to the motion of said boat hull angularly with respect to said deflectors; and a closure plate having forward and aft edges, said plate being slidably attached to said hull in a position partially to cover said port, said plate having a plurality of slots opening through the forward edge thereof which receives said elongated members, respectively; and means for selectively moving said plate with respect to said hull for varying the area of said port thereby controlling the flow of fluid into said port.

3. In combination, a boat hull having an intake port in the bottom of said hull, said port having forward and aft ends; a strainer for covering said port, said strainer comprising a plurality of elongated members having leading and trailing ends, said members being spaced apart and parallel and extending longitudinally of said hull, the leading ends of the first ones of said members being fixedly attached to said hull adjacent the forward end of said port, the leading ends of second ones of said members being pivotally attached to said hull adjacent the forward end of said port for swinging movement about axes extending transversely of said hull, said first and second member being arranged alternatively; two elongated keels depending from the bottom of said hull and extending longitudinally of said hull for the distance of and along opposite sides, respectively, of said port for deflecting fluid into said port in response to the motion of said boat hull angularly with respect to said deflectors.

4. In combination, a boat hull having an intake port in the bottom of said hull, said port having forward and aft ends; a strainer covering said port, said strainer comprising a plurality of elongated members having leading and trailing ends, said members being spaced apart and parallel and extending longitudinally of said hull, the

leading ends of first ones of said members being fixedly attached to said hull adjacent to the forward end of said port, the leading ends of second ones of said members being pivotally attached to said hull adjacent to the forward end of said port for swinging movement about axes extending transversely of said hull, said first and second member being arranged alternately; and a closure plate having opposite forward and aft edges, said plate being slidably attached to said hull in position partially to cover said port, said plate having a plurality of slots opening through the forward edge thereof which receive said elongated members, respectively, and means for selectively moving said plate with respect to said hull for varying the area of said port thereby controlling the flow of fluid into said port.

5. In combination, a boat hull having a longitudinal axis of symmetry and a bottom provided with inner and outer bottom surfaces; an intake port in said bottom having forward and aft ends and opposite lateral edges extending axially of said hull; a plurality of axially extending and equally spaced elongated members covering said port, said members having leading and trailing ends, said members being alternately fixedly and pivotally attached to said hull at said leading ends proximate to said forward end of said port, predetermined ones of said fixedly attached members being disposed adjacent to the center and lateral edges of said port, said fixedly attached members having elastic properties and being free to vibrate, all of said members being unattached at said trailing ends and overhanging said aft end forming a strainer overlying said port; a plurality of push rods connected to said pivotally attached members proximate to said trailing ends thereof, said push rods passing through said hull bottom whereby said pivotally attached members may be swung away from said outer bottom surface of said hull, means yieldably urging said pivotally attached members toward said port; two allochiral sister keels L shaped in cross-section having opposite ends, said keels comprising a mounting flange and a keel portion perpendicular thereto, said flanges being secured to said outer bottom surface on opposite sides, respectively, of said port, said keel portions extending longitudinally of said hull, said flanges extending laterally inwardly toward each other, said mounting flanges having inwardly facing grooves which extend longitudinally from the aft ends of said sister keels adjacent to said bottom surface; and a forked closure plate comprising a plurality of elongated parallel tines joined at one end thereof, said plate being slidably positioned in said grooves with said members and said tines in spaced juxtaposition whereby said plate may be slid back and forth on said outer bottom surface alternately to decrease and increase the area of said opening without impairing the movement of said vibratory and pivotal members, an actuating member fixedly attached at a central location to said plate whereby force may be applied to said actuating member to slide said plate.

6. In combination, a boat hull having a longitudinal axis and a bottom provided with an intake port, an engine mounted in said hull, a pump mounted in said hull and having inlet and exhaust ducts, said pump being operatively connected to said engine and said inlet duct being registered with said intake port, means including said exhaust duct for propelling said bull in response to operation of said engine and pump, said port having forward and aft edges extending transversely of said hull and opposite lateral edges extending longitudinally of said hull, a plurality of elongated, parallel and spaced apart members having leading and aft ends, respectively, covering said port, said members extending longitudinally of said hull, alternate members being pivotally connected to said hull at the leading ends thereof for at least swinging movement toward and away from said hull bottom, the remaining alternate members being fixedly connected to said hull at the leading ends thereof, means for selectively pivoting the first mentioned alternate members toward and away from said hull bottom, a plurality of push rods connected to said pivotally connected members, said push rods being mounted in said hull bottom for selective 0pposite rectilinear movement in directions which move said pivotally connected members toward and away from, respectively, said bottom, means for moving said push rods in a direction to move said pivotally connected members toward said bottom, two elongated spaced apart and parallel keel members mounted on and depending from said bottom, said keel members extending longitudinally of said hull on opposite sides, respectively, of said port, said keel members being adjacent to the respective lateral port edges, said keel members extending for the longitudinal distance of said port, groove means provided on opposite lateral sides of said port adjacent to the aft edge thereof, a flat plate mounted in said groove means for movement to a first position in which said port is partially covered and to a second position in which said port is less partially covered, said plate having a plurality of spaced apart parallel slots which movably receive the aft end portions of said elongated members, said slots having a length suflicient to permit movement of said plate between said first and second positions, and means for selectively movmg said plate to a given position between said first and second positions.

7. In combination, a boat hull having a longitudinal axis and a bottom provided with an intake port, an engine mounted in said hull, a pump mounted in said hull and having inlet and exhaust ducts, said pump being operatively connected to said engine and said inlet duct being registered with said intake port, means including said exhaust duct for propelling said hull in response to opera tion of said engine and pump, said port having forward and aft edges extending transversely of said hull and opposite lateral edges extending longitudinally of said hull, a plurality of elongated parallel and spaced apart members having leading and aft ends, respectively, covering said port, said members extending longitudinally of said hull, alternate members being pivotally connected to said hull at the leading ends thereof for swinging movement toward and away from said hull bottom, the remainingalternate members being fixedly connected to said hull at the leading ends thereof, means for selectively pivoting the first mentioned alternate members toward and away from said hull bottom, a plurality of push rods connected to said pivotally connected members, said push rods being mounted in said hull bottom for selective opposite rectilinear movement in directions which move said pivotally connected members toward and away from, respectively, said bottom, means for moving said push rods in a direction to move said pivotally connected members toward said bottom, two elongated spaced apart and parallel keel members mounted on and depending from said bottom, said keel members extending longitudinally of said hull on opposite sides, respectively, of said port, said keel members being adjacent to the respective lateral port edges, said keel members extending for the longitudinal distance of said port, groove means provided on opposite lateral sides of said port adjacent to the aft edge thereof.

8. In combination, a boat hull having a longitudinal axis and a bottom provided with an intake port, an engine mounted in said hull, a pump mounted in said hull and having inlet and exhaust ducts, said pump being operatively connected to said engine and said inlet duct being registered with said intake port, means including said exhaust duct for propelling said hull in response to operation of said engine and pump, said port having forward and aft edges extending transversely of said hull and opposite lateral edges extending longitudinally of said hull, two elongated spaced apart and parallel keel members mounted on and depending from said bottom, said keel members extending longitudinally of said hull on opposite sides, respectively, of said port, said keel members being adjacent to the respective ones of said lateral edges, said keel members extending for at least the longitudinal distance of said port and defining the opposite sides of an open space free of tangible structure that projects beneath said port, said space having an open forward end, an open aft end and an open bottom communicating with said space, each of said keel members being impervious to water and having a surface facing the other of said keel members, whereby water is deflected into said port in response to turning motion of said hull.

9. In combination, a boat hull having a longitudinal axis and a bottom provided with an intake port, an engine mounted in said hull, a pump mounted in said hull and having inlet and exhaust ducts, said pump being operatively connected to said engine and said inlet duct being registered with said intake port, means including said exhaust duct for propelling said hull in response to operation of said engine and pump, said port having forward and aft edges extending transversely of said hull and opposite lateral edges extending longitudinally of said hull, two elongated spaced apart and parallel keel members mounted on and depending from said bottom, said keel members extending longitudinally of said hull on opposite sides, respectively, of said port, said keel members being adjacent to the respective lateral port edges, said keel members extending for at least the longitudinal distance of said port and defining opposite sides of a space which extends beneath said port, groove means provided on opposite lateral sides of said port adjacent to the aft edge thereof, a flat plate mounted in said groove means for movement to a first position in which said port is partially covered and to a second position in which said port is less partially covered, and means for selectively moving said plate to a given position between said first and second positions.

10. In combination, a boat hull having a longitudinal axis and an intake port in the bottom thereof, a plurality of elongated parallel and spaced apart members having leading and aft ends, respectively, covering said port, said members extending longitudinally of said hull, alternate members being pivotally connected to said hull at the leading ends thereof for swinging movement toward and away from said hull bottom, the remaining alternate members being fixedly connected to said hull at the leading ends thereof, means for selectively pivoting the firstmentioned alternate members toward and away from said hull bottom.

11. In combination, a boat hull having a longitudinal axis and a bottom provided with an intake port, an engine mounted in said hull, a pump mounted in said hull and having inlet and exhaust ducts, said pump being operatively connected to said engine and said inlet duct being registered with said intake port, means including said exhaust duct for propelling said hull in response to operation of said engine and pump, said port having forward and aft edges extending transversely of said hull and opposite lateral edges extending longitudinally of said hull, two elongated keel members mounted on and depending from said bottom, said keel members extending longitudinally of said hull on opposite sides, respectively, of said port,

said keel members being adjacent to the respective ones of said lateral edges, said keel members defining the opposite sides of an open space free of tangible structure that projects beneath said port, said space having an open forward end, an open aft end and an open bottom communicating with said space, each of said keel members being impervious to water and having a surface facing the other of said keel members, whereby water is deflected into said port in response to turning motion of said hull.

12. In combination, a boat hull having a longitudinal axis and a bottom provided with an intake port, an engine mounted in said hull, a pump mounted in said hull and having inlet and exhaust ducts, said pump being operatively connected to said engine and said inlet duct being registered with said intake port, means including said exhaust duct for propelling said hull in response to operation of said engine and pump, said port having forward and aft edges extending transversely of said hull and opposite lateral edges extending longitudinally of said hull, a plurality of elongated and spaced apart members having leading and aft ends, respectively, covering said port, said members extending longitudinally of said hull, a first portion of said members being pivotally connected to said hull at the leading ends thereof for swinging movement toward and away from said hull bottom, the remaining portion of said members being fixedly connected to said hull at the leading ends thereof, means for selectively pivoting said first portion of members toward and away from said hull bottom, a plurality of push rods connected to said pivotally connected members, said push rods being mounted in said hull bottom for selective opposite rectilinear movement in directions which move said pivotally connected members toward and away from, respectively, said bottom, means for moving said push rods in a direction to move said pivotally connected members toward said bottom.

13. In combination, a boat hull having a longitudinal axis and a bottom provided with an intake port, an engine mounted in said hull, a pump mounted in said hull and having inlet and exhaust ducts, said pump being operatively connected to said engine and said inlet duct being registered with said intake port, means including said exhaust duct for propelling said hull in response to operation of said engine and pump, said port having forward and aft edges extending transversely of said hull and opposite lateral edges extending longitudinally of said hull, a plurality of elongated and spaced apart members having leading and aft ends, respectively, covering said port, said members extending longitudinally of said hull, a first portion of said members being pivotally connected to said 1 1 hull at the leading ends thereof for swinging movement toward and away from said hull bottom, the remaining portion of said members being fixedly connected to said hull at the leading ends thereof, and means for selectively pivoting said first portion of members toward and away from said hull bottom.

14. In combination, a boat hull having a longitudinal axis and a bottom provided with an intake port, an engine mounted in said hull, a pump mounted in said hull and having inlet and exhaust ducts, said pump being operatively connected to said engine and said inlet duct being registered with said intake port, means including said exhaust duct for propelling said hull in response to operation of said engine and pump, said port having forward and aft edges extending transversely of said hull and opposite lateral edges extending longitudinally of said hull and a plurality of elongated members having leading and trailing ends, said members being spaced apart and extending jacent to the forward end of said port, the leading ends of second ones of said members being pivotally attached to said hull adjacent to the forward end of said port for swinging movement about axes extending transversely of said hull.

References Cited by the Examiner UNITED STATES PATENTS 1,023,205 4/1912 Jensen 115-14 1,689,114 10/1928 Choquette 1150.5 1,751,421 3/1930 Reid 210-499 X 2,024,274 12/ 1935 Campini.

2,435,401 2/ 1948 Martin 6035.6 3,040,695 6/1962 Austin 115--14 3,076,426 2/1963 Alexander et al 11514 MILTON BUCHLER, Primary Examiner.

ANDREW H. FARRELL, Examiner. 

8. IN COMBINATION, A BOAT HULL HAVING A LONGITUDINAL AXIS AND A BOTTOM PROVIDED WITH AN INTAKE PORT, AN ENGINE MOUNTED IN SAID HULL, A PUMP MOUNTED IN SAID HULL AND HAVING INLET AND EXHAUST DUCTS, SAID PUMP BEING OPERATIVELY CONNECTED TO SAID ENGINE AND SAID INLET DUCT BEING REGISTERED WITH SAID INTAKE PORT, MENS INCLUDING SAID EXHAUST DUCT FOR PROPELLING SAID HULL IN RESPONSE TO OPERATION OF SAID ENGINE AND PUMP, SAID PORT HAVING FORWARD AND AFT EDGES EXTENDING TRANSVERSELY OF SAID HULL AND OPPOSITE LATERAL EDGES EXTENDING LONGITUDINALLY OF SAID HULL, TWO ELONGATED SPACED APART AND PARALLEL KEEL MEMBERS MOUNTED ON AND DEPENDING FROM SAID BOTTOM, SAID KEEL MEMBERS EXTENDING LONGITUDINALLY OF SAID HULL ON OPPOSITE SIDES, RESPECTIVELY, OF SAID PORT, SAID KEEL MEMBERS BEING ADJACENT TO THE RESPECTIVE ONES OF SAID LATERAL EDGES, SAID KEEL MEMBERS EXTENDING FOR AT LEAST THE LONGITUDINAL DISTANCE OF SAID PORT AND DEFINING THE OPPOSITE SIDES OF AN OPEN SPACE FREE OF TANGIBLE STRUCTURE THAT PROJECTS BENEATH SAID PORT, SAID SPACE HAVING AN OPEN FORWARD END, AN OPEN AFT END AND AN OPEN BOTTOM COMMUNICATING WITH SAID SPACE, EACH OF SAID KEEL MEMBERS BEING IMPERVIOUS TO WATER AND HAVING A SURFACE FACING THE OTHER OF SAID KEEL MEMBERS, WHEREBY WATER IS DEFLECTED INTO SAID PORT IN RESPONSE TO TURNING MOTION OF SAID HULL. 